compare_routes

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond annotations (readOnlyHint, destructiveHint, idempotentHint, openWorldHint), description adds 'Read-only, no authentication, no booking side effects' and mentions 'responses may include commission-eligible external booking links'. No contradictions with annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three sentences, front-loaded with main action, then usage guidelines, then behavioral notes. No wasted words.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema, but description hints at return content (external booking links). For a comparison tool, this sets reasonable expectations. Could mention return format (text/table) but acceptable.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema has 100% description coverage for the single parameter 'routes' with nested objects. Description does not add much beyond schema, but the phrase 'two or more' helps clarify minimum length. Baseline of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states 'Compare two or more airport route pairs side by side' with specific verb and resource. It distinguishes from siblings by naming when to use search_travel_options (one dated route) and get_airport_info (single airport lookup).

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly states when to use this tool ('choosing between alternate origins, destinations, or airports') and when to use alternatives (search_travel_options for one dated route, get_airport_info for single airport).

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.